Clinical Characteristics, Management Strategies, and Outcomes of Non-ST-Segment-Elevation Myocardial Infarction Patients With and Without Prior Coronary Artery Bypass Grafting

Background There are limited data on the management strategies, temporal trends and clinical outcomes of patients who present with non-ST-segment-elevation myocardial infarction and have a prior history of CABG. Methods and Results We identified 287 658 patients with non-ST-segment-elevation myocardial infarction between 2010 and 2017 in the United Kingdom Myocardial Infarction National Audit Project database. Clinical and outcome data were analyzed by dividing into 2 groups by prior history of coronary artery bypass grafting (CABG): group 1, no prior CABG (n=262 362); and group 2, prior CABG (n=25 296). Patients in group 2 were older, had higher GRACE (Global Registry of Acute Coronary Events) risk scores and burden of comorbid illnesses. More patients underwent coronary angiography (69% versus 63%) and revascularization (53% versus 40%) in group 1 compared with group 2. Adjusted odds of receiving inpatient coronary angiogram (odds ratio [OR], 0.91; 95% CI, 0.88-0.95; P<0.001) and revascularization (OR, 0.73; 95% CI, 0.70-0.76; P<0.001) were lower in group 2 compared with group 1. Following multivariable logistic regression analyses, the OR of in-hospital major adverse cardiovascular events (composite of inpatient death and reinfarction; OR, 0.97; 95% CI, 0.90-1.04; P=0.44), all-cause mortality (OR, 0.96; 95% CI, 0.88-1.04; P=0.31), reinfarction (OR, 1.02; 95% CI, 0.89-1.17; P=0.78), and major bleeding (OR, 1.01; 95% CI, 0.90-1.11; P=0.98) were similar across groups. Lower adjusted risk of inpatient mortality (OR, 0.67; 95% CI, 0.46-0.98; P=0.04) but similar risk of bleeding (OR,1.07; CI, 0.79-1.44; P=0.68) and reinfarction (OR, 1.13; 95% CI, 0.81-1.57; P=0.47) were observed in group 2 patients who underwent percutaneous coronary intervention compared with those managed medically. Conclusions In this national cohort, patients with non-ST-segment-elevation myocardial infarction with prior CABG had a higher risk profile, but similar risk-adjusted in-hospital adverse outcomes compared with patients without prior CABG. Patients with prior CABG who received percutaneous coronary intervention had lower in-hospital mortality compared with those who received medical management.